Understand
On the blockchain, every transfer is public and stays on record for good. You don't always know who is behind an address, but you can follow its money, transaction after transaction. That is the job of on-chain investigators: analysts, exchanges, police, journalists. Chaindoku turns their methods into logic puzzles.
A public blockchain such as Bitcoin or Ethereum is a ledger open to everyone. Each transaction shows the sending address, the receiving address, the amount and the block it was recorded in. A block explorer, such as Etherscan for Ethereum, lets anyone look it all up from a browser.
An address shows no name: it is a pseudonym. The whole art of investigating is linking these pseudonyms to each other, then to services or people, by cross-checking clues. Exactly like in a Chaindoku grid.
In real life
Transactions are grouped into numbered blocks that follow one another in time. The block number dates every move: it tells what happened before, and what happened after.
In the game
The grid's columns are the blocks, from left to right. “She signed in block 3” places an address in column B3.
In real life
Every transaction that moves funds away from their origin is a hop. Analysis tools measure the distance between an address and a theft, a ransom or an exchange this way: one hop, two hops, ten hops.
In the game
The grid's rows are the hops: hop 1 at the top, right next to the origin, and lower down the funds that have moved further away.
In real life
Analysts group the addresses they attribute to the same entity. A classic example on Bitcoin: addresses spent together in one transaction often belong to the same wallet. A cluster can stand for an exchange, a service or a group.
In the game
The colored zones of the grid are clusters. Once every address is placed, the culprit is the only one sharing the victim's cluster.
In real life
A mixer blends the funds of many users, splits them and delays them to blur the trail. The trail does not vanish, though: every input and output stays on record, and amounts and timing sometimes give the links away.
In the game
The mixer is a marker and a zone of the grid: two cases put it at the heart of the puzzle.
In real life
A bridge moves funds from one blockchain to another. Launderers use bridges to break the trail by switching chains, and bridges themselves are prime targets for hackers.
In the game
One case plays out on both sides of a hacked bridge, where each side blames the other.
In real life
To spend the money, you often have to go through an exchange. Regulated exchanges check their customers' identity: that is often where an address gets its name back, at a court's request.
In the game
The grid's CEX clusters are these exchanges. One case shows what happens when someone lends their account to scammers.
In real life
Authorities put some addresses on sanctions lists, and a stablecoin issuer can freeze an address: its tokens can no longer move. Exchanges refuse funds coming from them.
In the game
On the grid, a sanctioned or frozen address is a hatched cell where no one can be placed. One case follows sanctioned loot all the way to its exit.
In real life
Very large wallets are watched closely: their moves shift markets. A wallet asleep for years that wakes up draws every eye.
In the game
Two cases start from these signals: a giant transfer that raised no alert, and an old wallet that moves for a single transfer.
Linking two addresses is a more or less solid hypothesis, not proof: analysts speak in degrees of confidence. Some cryptocurrencies hide amounts and addresses, and mixers and bridges make the reading harder. But on a public blockchain nothing is erased: a cold trail can heat up again years later.
No specialist software needed: in Chaindoku, the trail is already drawn on the grid. It's up to you to place the addresses, cross-check the clues and unmask the culprit.
The tracing cases
300 euros to lend your account for a month. Then the police ring the doorbell.
The radar was meant to see everything. That night, a colossal transfer went by without a beep.
It promised anonymity. The coordinator may have sold who sent what.
A wallet asleep for years wakes up, just long enough for one move.
Split, mixed, delayed, recombined: the loot went through a maze.
4 a.m., every screen in the hospital shows the same ransom note.
Sanctioned loot goes down step by step, until it comes out clean.